They are relatively large lobsters with a cylindrical body covered with sharp spines (hence the genus name, meaning "spiny shrimp"). The carapace has a well-developed rostrum. The eyes are very small and lack pigment, while the antennae are long and whiplike. The telson and uropods are powerful. The first three pairs of walking legs end in claws. The first pair of claws is symmetrical, and ends in long fingers covered with sharp spines on cutting edges, but without hairs. The second pair of walking legs is much longer than the third pair. Both species reach a length of 40 centimetres (16 in).[1]